Political theology as we know it today reacts against the attempt to insulate theology from political theory which has generally characterised the modern era. This text considers the intellectual parentage of the idealist historicism of the 19th century, which the author claims is still entrammelled in the suspicions and inhibitions from which it has wanted to break free. The author contends that to pass beyond suspicion and totalized criticism of politics and to achieve a positive reconstruction of political thought, theology must reach back behind the modern tradition, achieving a fuller, less selective reading of the Scriptures and learning from an older politico-theological discourse which flourished in the patristic, medieval and Reformation periods. Central to that discourse was a series of questions about authority, generated by Jesus proclamation of the Kingdom of God.